multi-db support

gistfile1.txt

package postgres:api {
  interface connection {
    query: func(...) -> ...;
    execute: func(...) -> ...;
  }
  interface connections {
    *: connection;
  }
  interface runtime-connections {
    resource connection = resourceify(connection);
    open: func(name: string) -> connection;
  }
}

world my-single-db-world {
  import postgres:api/connection;
}
world my-declarative-multi-db-world {
  import postgres:api/connections;
}
world my-dynamic-db-world {
  import postgres:api/runtime-connections;
}
world or-heck-maybe-i-do-both {
  import postgres:api/connections;
  import postgres:api/runtime-connections;
}